The present paper uses the relationship between sawtooth wave’s amplitude and time’s linear code to test and analyze a spectrometer. The result shows that the sampling time is associated with the integration time and the sampling interval closely relates with integral time, and the fluctuation range of sampling interval was further explored. This paper provides the reference of the integral time for the analysis focused on spectrum time characteristic, proposes a method to evaluate the dynamic time properties, and contributes to the assessment and application of the dynamic characteristics of the spectrum.